This invention relates to a device for measuring a cloth thickness and a method for measuring a cloth thickness, and more specifically, relates to a device and a method for measuring the thickness of a cloth when the predetermined pressing force is applied to the cloth in order to previously ascertain the suitability of fixing a button, a grommet and the like to a variety of cloths.
Generally, a button, a grommet and the like (hereinafter simply referred to as a “button”) are fixed to a cloth such as clothing by the following way. First, the button is held by an upper fixing die and a button-fixing member such as an eyelet and a prong is supported on a lower fixing die, with the cloth placed between the upper and lower dies. After that, by operating a pressing machine, the upper die is caused to press against the lower die with a force of about 200 to 300 N. As a result of the pressing, a part of the fixing member is swaged after piercing the cloth, so that the button is locked on the cloth by the swaged part. The cloth on which the button has been fixed is partially thinned as compressed by the above swaged part. Here, the degree of being thinned varies depending on cloth types and initial thicknesses or a fixing member as used, especially the size, material, etc. of a part of the fixing member which pierces a cloth. Accordingly, if a combination of a cloth, a button and a button-fixing member is unsuitable, defects may be caused as follows: That is, a cloth can be easily breakable when the cloth is excessively thinned with a button fixed thereon, or a button can easily come off a cloth when the thinning of the cloth is insufficient with a poor compression by a swaged part. In order to prevent such fixing defects, conventionally, a thickness of a cloth with a button fixed thereon is previously ascertained by applying the same force to the cloth as the above-mentioned pressing force and then measuring the thickness of the cloth at that time, which is almost identical to the thickness of the cloth to which a button has been fixed. In this way, a button and a fixing member which are considered suitable for the cloth are selected.
A prior-art device for measuring a cloth thickness is disclosed in Japanese Patent No. 2989589. The device for measuring a cloth thickness is constructed as follows: The device includes a stationary part at one end of an arc-shaped frame and a movable member at the other end of the frame. After a cloth as a measurement target is placed between the stationary part and the movable member, the cloth is gradually compressed by moving the movable member toward the stationary part while rotating the movable member by operating a dial operational part. While the force or pressure being applied to the cloth is being detected from a distortion of the arc-shaped frame, the movable member is stopped when the force reaches the predetermined value (for example, 200 N). The cloth thickness at the time of stopping the movable member can be ascertained from the amount of displacement of the movable member.
However, for the prior-art device for measuring a cloth thickness, it is necessary to continue to rotate the operational part until the force applied to a cloth reaches the predetermined value, so it takes time and effort in measuring. In addition, since the movable member is pressed to the cloth while being rotated, non-negligible measurement errors may occur depending on a cloth type due to rotational friction.
[Patent document 1] Japanese Patent No. 2989589